Compounds of Groups III-A and V-A elements of the Periodic Table can be prepared in many different ways including molecular beam epitaxy, metal organic chemical vapor deposition, liquid phase epitaxy, ion implantation, and others. The first three are epitaxial whereas the fourth is not. Molecular beam epitaxy (MBE) is often used for growing or preparing the compounds.
Preparation of the compounds can be done at a high temperature range, middle temperature range, and low temperature range. The compounds prepared at a high temperature range are also referred to herein as high range compounds which are characterized by single crystal structure. The compounds prepared at a middle temperature range are also referred to herein as mid range compounds which are characterized by single crystal structure with a larger lattice parameter than is obtained at the high temperature range. The compounds prepared at a low temperature are also referred to herein as low range compounds which are characterized by amorphous structure. For gallium arsenide, the best known of the Groups III-A and V-A compounds, the high temperature range is above about 340.degree. C., the middle temperature range is in the approximate range of 215.degree.-340.degree. C., and the low temperature range is below about 215.degree. C.
Prior to this development, amorphous gallium arsenide was not desirable because of its poor electrical properties.
The most important use of gallium arsenide is as a semiconductor. For certain applications and to be useful as a semiconductor, gallium arsenide has single crystal structure and high electrical conductivity.